Plasma brain natriuretic peptide as a prognostic indicator in patients with primary pulmonary hypertension

Genomics and proteomics of pulmonary vascular disease

Study of RNA and proteins in cells of both normal and diseased tissues is providing researchers with new knowledge of disease pathologies. While still in its early stages, high-throughput expression analysis is improving our understanding of the pathogenesis of pulmonary arterial hypertension (PAH). While many studies have used microarray and proteomic analyses as "hypothesis-generating" tools, the technologies also have potential to identify and quantify biomarkers of disease. To date, many of the published studies have examined gene expression profiles of tissue biopsies, others have utilized cells from peripheral blood. Microarray technology has been employed successfully in the investigation of a diverse array of human diseases. The potential of high-throughput expression analysis to improve our understanding of the pathogenesis of PAH is highlighted in this review. Proteomic studies of PAH and pulmonary vascular diseases in general have been little utilized thus far. To date, such studies are few and no consistent biomarker has emerged from studies of either plasma or blood cells from idiopathic pulmonary arterial hypertension (IPAH) patients. The studies of both lung tissue and lymphocytes are perhaps more revealing and suggest that changes in the cytoskeletal machinery may play a role in the pathogenesis of idiopathic pulmonary arterial hypertension. The oncology literature has demonstrated the utility of gene microarray analysis to predict important outcomes such as response to therapy and survival. It is likely that in the near future, gene microarrays and proteomic analyses will also be employed in a pharmacogenomics approach in PAH, helping to identify the most appropriate therapies for individual patients.

Biomarkers in pulmonary hypertension: what do we know?

Pulmonary hypertension (PH) is a hemodynamic condition that has a poor prognosis and can lead to right-sided heart failure. It may result from common diseases such as left-sided heart or lung disease or may present as the rare entity of idiopathic pulmonary arterial hypertension. Biomarkers that specifically indicate the pathologic mechanism, the severity of the disease, and the treatment response would be ideal tools for the management of PH. In this review, markers related to heart failure, inflammation, hemostasis, remodeling, and endothelial cell-smooth muscle cell interaction are discussed, and their limitations are emphasized. Anemia, hypocarbia, elevated uric acid, and C-reactive protein levels are unspecific markers of disease severity. Brain natriuretic peptide and N-terminal fragment of pro-brain natriuretic peptide have been recommended in current guidelines, whereas other prognostic markers, such as growth differentiation factor-15, osteopontin, and red cell distribution width, are emerging. Chemokines of the CC family and matrix metalloproteases have been linked to the vascular pathologic mechanisms, and new markers such as apelin have been described. Circulating endothelial and progenitor cells have received much attention as markers of disease activity, but with controversial findings. A lack of standards for cell isolation and characterization methods and differences in the pathologic mechanisms of the investigated patients may have contributed to the discrepancies. In conclusion, although several promising markers have been identified over the past few years, the development of more specific markers, standardization, and prospective validation are warranted.

Reproducibility of intracardiac and transpulmonary biomarkers in the evaluation of pulmonary hypertension

Intracardiac and transpulmonary levels of natriuretic peptides (NPs) and cyclic guanosine monophosphate (cGMP) provide insight into the pathophysiology of pulmonary hypertension (PH) secondary to left-heart failure but have not been evaluated in established or suspected pulmonary arterial hypertension (PAH). Demonstrating adequate reproducibility of these markers is an important precursor to further study. We hypothesized that the reproducibility of intracardiac and transpulmonary NPs and cGMP is similar to the reproducibility of these markers sampled from the peripheral venous circulation. In outpatients undergoing right-heart catheterization for PH, blood samples were obtained from a peripheral venous site, superior vena cava, inferior vena cava, coronary sinus, pulmonary artery, and pulmonary capillary wedge position. At each site, a repeat sample was collected approximately 60 seconds after the initial measurement. Reproducibility was assessed using the slope of the regression line between initial and follow-up levels. We enrolled 10 patients: Six had PAH, two had pulmonary venous hypertension, and two had normal pulmonary pressure. At all sites, the slopes of the regression lines for BNP were close to identity. BNP was generally more reproducible than NT-pro-BNP. For the NPs and cGMP, reproducibility at intracardiac and transpulmonary sites was similar to the peripheral venous site. Reproducibility of NPs was not influenced by PH severity, access site, or time between measurements. The two patients with the highest transpulmonary pressure gradients had high transpulmonary BNP uptake, but their transpulmonary cGMP gradients were negative. In patients evaluated for PH, reproducibility of NPs and cGMP at intracardiac and transpulmonary sites is high and is comparable to that of peripheral venous measurements.

Short-term improvement in pulmonary hemodynamics is strongly predictive of long-term survival in patients with pulmonary arterial hypertension

Abstract Hemodynamic measurements provide important parameters for determining prognosis and therapy in patients with pulmonary arterial hypertension (PAH). Current guidelines do not incorporate the possible predictive value of individual changes in hemodynamic variables during the disease time course, and there is no consensus about the time point for hemodynamic reevaluation. We aimed to assess the long-term prognostic value of short-term changes in hemodynamic parameters. The study included 122 patients with PAH from the Giessen Pulmonary Hypertension Registry who underwent hemodynamic evaluation at baseline and at 16 weeks (±2.5 standard deviations [SDs]; range: 4-29 weeks) after initial assessment. At baseline, mean pulmonary vascular resistance (PVR) was 1,109 dyn s cm(-5), and 82% of patients were in World Health Organization (WHO) functional class III or IV. Fifty patients died, and 2 underwent lung transplantation during long-term observation (≤10 years; mean: 4.7 years). Kaplan-Meier estimates for transplant-free survival were 93.3%, 76.1%, 57.8%, and 53.1% at 1, 3, 5, and 7 years, respectively. When assigned to prognostic groups, improvements in cardiac output of >0.22 L min(-1) (hazard ratio [HR]: 2.05; [Formula: see text]) and a decrease in PVR of >176 dyn s cm(-5) (HR: 1.89; [Formula: see text]) at 4-29 weeks were associated with long-term transplant-free survival. Changes in mean pulmonary arterial pressure did not predict long-term prognosis. Of 2 noninvasive parameters assessed in this selected patient group, change in WHO functional class, but not in 6-minute walk distance, predicted long-term prognosis. Short-term assessment of changes in hemodynamic parameters at [Formula: see text] after initial invasive evaluation is useful to determine long-term prognosis in patients with PAH.

Novel therapeutic approaches to preserve the right ventricle

The right ventricle (RV) is increasingly recognized for its role in heart disease. In fact, RV function is a strong predictor of outcome in patients with cardiovascular disease. Although the focus in heart failure has been on the left ventricle (LV), recently the spotlight has been shifting to include the RV. The RV and LV have different embryological origins and respond differently to stressors and to therapies. Newer therapies targeting the RV have been investigated in an attempt to improve right-ventricular adaptation to cardiovascular diseases. In this review, we summarize the differences between the RV and LV and focus on novel therapies that target the RV.

Heart failure and chronic obstructive pulmonary disease: the challenges facing physicians and health services

Pulmonary disease is common in patients with heart failure, through shared risk factors and pathophysiological mechanisms. Adverse pulmonary vascular remodelling and chronic systemic inflammation characterize both diseases. Concurrent chronic obstructive pulmonary disease presents diagnostic and therapeutic challenges, and is associated with increased morbidity and mortality. The cornerstones of therapy are beta-blockers and beta-agonists, whose pharmacological properties are diametrically opposed. Each disease is implicated in exacerbations of the other condition, greatly increasing hospitalizations and associated health care costs. Such multimorbidity is a key challenge for health-care systems oriented towards the treatment of individual diseases. Early identification and treatment of cardiopulmonary disease may alleviate this burden. However, diagnostic and therapeutic strategies require further validation in patients with both conditions.

Baseline and follow-up 6-min walk distance and brain natriuretic peptide predict 2-year mortality in pulmonary arterial hypertension

BACKGROUND

Six-minute walk distance (6MWD) and brain natriuretic peptide (BNP) levels at baseline and after initiation of treatment have been associated with survival in patients with pulmonary arterial hypertension. Our objective was to determine the individual and additive ability of pretreatment and posttreatment 6MWD and BNP to discriminate 2-year survival in patients with pulmonary arterial hypertension.

METHODS

We included patients enrolled in two randomized clinical trials of ambrisentan who had 2-year follow-up (N 5 370). 6MWD and BNP were assessed before and after 12 weeks of treatment. Receiver operating characteristic curve analyses were performed to identify optimal cutoffs that defi ned subgroups with a high 2-year mortality. Classifi cation and regression tree analysis was used to determine the incremental prognostic value of combined assessments.

RESULTS

6MWD at baseline and after 12 weeks of therapy were similarly discriminatory of 2-year survival (c-statistics 5 0.77 [95% CI 0.70-0.84] and 0.82 [95% CI 0.75-0.88], respectively), whereas change in 6MWD from baseline to week 12 was not discriminating. The same observation was true of BNP at baseline and after 12 weeks of therapy (c-statistics 5 0.68 [95% CI 0.60-0.76] and 0.74 [95% CI 0.66-0.82], respectively). After consideration of baseline 6MWD, there was no prognostic information added by the week 12 6MWD or BNP at either time point.

CONCLUSIONS

6MWD and BNP values at baseline or week 12 identifi ed a population with an elevated risk of death at 2 years. A repeat assessment of 6MWD or BNP after 12 weeks of ambrisentan therapy did not provide additional prognostic information beyond that obtained from baseline values.

Surgical strategy for severe aortic hypoplasia and aortic stenosis with ventricular septal defect and normal left ventricle

At our institution, the strategy for patients with bicuspid aortic valve, aortic valve stenosis (<5 mm), and aortic hypoplasia [hypoplastic aortic arch, coarctation of the aorta (CoA), or interrupted aortic arch (IAA)] with ventricular septal defects (VSDs) as well as normal left ventricular (LV) volume and mitral valve size consists of two parts. The Norwood operation is applied as the first palliation for this group of patients. Second, the decision whether the patients are to undergo the Rastelli operation or a univentricular repair is made depending on the size of the right ventricle after the Norwood operation. This study aimed to examine whether the aforementioned surgical strategy for this group of patients is adequate or not. Seven patients undergoing the Norwood operation as the first palliation for bicuspid aortic valve, aortic valve stenosis (<5 mm), and aortic hypoplasia with VSDs as well as normal LV volume and mitral valve size between February 2005 and March 2010 at Kitasato University Hospital and the Gunma Children's Medical Center were reviewed. Postoperative serum B-type natriuretic peptide (BNP) and central venous pressure (CVP) were measured in the patients undergoing the staged Norwood-Rastelli operation to assess whether the authors' right ventricular end-diastolic volume index (RVEDVI) cutoff (80 % of normal) is adequate. At this writing, all seven patients are alive after a mean follow-up period of 58.8 ± 17.8 months. They all had aortic valve stenosis of <5 mm and a bicuspid aortic valve. Four patients had a diagnosis of CoA with VSD, and three patients had IAA with VSD. Six patients underwent biventricular repair, and one patient had univentricular repair due to the small RVEDVI (74 % of normal). The patients with 80-90 % of normal RVEDVI had higher BNP and higher CVP than those with more than 90 % of normal RVEDVI after the Rastelli operation, whereas the patient undergoing the Fontan operation had a low BNP level. In conclusion, the described strategy for patients with severe aortic hypoplasia and aortic stenosis with VSD as well as normal LV and mitral valve size is reasonable.

Blood specimen biomarkers of inflammation, matrix degradation, angiogenesis, and cardiac involvement: a future useful tool in assessing clinical outcomes of COPD patients in clinical practice?

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible; this airflow limitation is both progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gasses. COPD is undoubtedly an umbrella term, and it seems unlikely that all patients with COPD have the same underlying disease processes; thus, there is a need for differential treatment of different subgroups. A potential solution is to find modifiable biomarkers that can assist in drug development and distinguish subgroups of COPD. With the exception of lung function tests, there are currently no well-validated biomarkers or surrogate endpoints that can be used to establish the efficacy of a drug for COPD. This article discusses biomarkers of inflammation (fibrinogen, C-reactive protein, pulmonary and activation-regulated chemokine/CC-chemokine ligand-18, serum surfactant protein D, interleukin (IL)-6, IL-8 and tumor necrosis factor α, complement factor C5a), angiogenesis factors as a part of the pathogenetic aspect in this disease (vascular endothelial growth factor, angiogenin, and IL-8), and matrix degradation biomarkers. Troponin and natriuretic peptides are presented as biomarkers of cardiac involvement in the light of COPD comorbidities. Trials based on research on known clinical variables such as FEV1, BODE, and 6MWT in combination with biomarkers from lung and blood specimens will probably clarify part of the prognosis and natural history of the disease. This will also represent an additional step in COPD phenotyping and new treatment possibilities.

Pim-1: A new biomarker in pulmonary arterial hypertension

Provirus integration site for Moloney murine leukemia virus (Pim-1) is an oncoprotein overexpressed in lungs from pulmonary arterial hypertension (PAH) patients and involved in cell proliferation via the activation of the NFAT/STAT3 signaling pathway. We hypothesized that Pim-1 plasma levels would predict the presence of PAH and correlate with disease severity. Pim-1 plasma levels were measured at the time of catheterization in 49 PAH patients, including nonvasoreactive ( n = 19) and vasoreactive idiopathic PAH (n = 5), and PAH related to connective tissue disease (n = 16) and congenital heart disease (n = 9). Fifty controls were also recruited. The capacity of Pim-1 to discriminate PAH from controls and its association with disease severity were assessed. Pim-1 plasma levels were higher in PAH than in controls (9.6 ± 4.0 vs. 7.2 ± 2.4 ng/mL, P < 0.01). Pim-1 appropriately discriminated proliferative PAH from controls (AUC = 0.78 to 0.94 using ROC curves). Among PAH patients, Pim-1 correlated with traditional markers of PAH severity. The 1-year survival was 97% and 47% for PAH patients with baseline Pim-1 levels lower and higher than 11.1 ng/mL, respectively (HR 11.4 (3.3-39.7); P < 0.01). After adjustment for hemodynamic and biochemical variables, Pim-1 levels remained an independent predictor of mortality (P < 0.01). Pim-1 is a promising new biomarker in PAH.

Diminazene aceturate improves autonomic modulation in pulmonary hypertension

We have previously demonstrated that diminazene aceturate (DIZE), a putative angiotensin 1-7 converting enzyme activator, protects rats from monocrotaline (MCT)-induced pulmonary hypertension (PH). The present study was conducted to determine if the beneficial effects of DIZE are associated with improvements in autonomic nervous system (ANS) modulation. PH was induced in male rats by a single subcutaneous injection of MCT (50 mg/kg). A subset of MCT rats were treated with DIZE (15 mg/kg/day) for a period of 21 days, after which the ANS modulation was evaluated by spectral and symbolic analysis of heart rate variability (HRV). MCT administration resulted in a significant (P<0.001) increase in the right ventricular systolic pressure (62 ± 14 mmHg) when compared with other experimental groups (Control: 26 ± 6; MCT + DIZE: 31 ± 7 mmHg), while DIZE treatment was able to decrease this pressure. Furthermore MCT-treated rats had significantly reduced total power of HRV than the controls. On the other hand, although not significant, a trend towards increased HRV was observed in the MCT + DIZE group (Control: 108 ± 47; MCT: 12 ± 8.86 and MCT + DIZE: 40 ± 14), suggesting an improvement of the cardiac autonomic modulation. This observation was further confirmed by the low-frequency/high-frequency index of spectral analysis (Control: 0.74 ± 0.62; MCT: 1.45 ± 0.78 and MCT + DIZE: 0.34 ± 0.49) which showed that DIZE treatment was able to recover the ANS imbalance observed in the MCT-induced pulmonary hypertensive rats. Collectively, our results demonstrate that MCT-induced PH is associated with a significant increase in sympathetic modulation and a decrease in HRV, which are markedly improved by DIZE treatment.

Biomarkers of cardiac dysfunction and mortality from community-acquired pneumonia in adults

Background

Cardiac dysfunction is common in acute respiratory diseases and may influence prognosis. We hypothesised that blood levels of N-terminal B-type natriuretic peptide (NT-proBNP) and high-sensitivity Troponin T would predict mortality in adults with community-acquired pneumonia.

Methods and Findings

A prospective cohort of 474 consecutive patients admitted with community-acquired pneumonia to two New Zealand hospitals over one year. Blood taken on admission was available for 453 patients and was analysed for NT-proBNP and Troponin T. Elevated levels of NT-proBNP (>220 pmol/L) were present in 148 (33%) and 86 (19%) of these patients respectively. Among the 26 patients who died within 30 days of admission, 23 (89%) had a raised NT-proBNP and 14 (53%) had a raised Troponin T level on admission compared to 125 (29%) and 72 (17%) of the 427 who survived (p values<0.001). Both NT-proBNP and Troponin T predicted 30-day mortality in age-adjusted analysis but after mutual adjustment for the other cardiac biomarker and the Pneumonia Severity Index, a raised N-terminal pro-brain natriuretic peptide remained a predictor of 30-day mortality (OR = 5.3, 95% CI 1.4–19.8, p = 0.013) but Troponin T did not (OR = 1.3, 95% CI 0.5–3.2, p = 0.630). The areas under the receiver-operating curves to predict 30-day mortality were similar for NT-proBNP (0.88) and the Pneumonia Severity Index (0.87).

Conclusions

Elevated N-terminal B-type natriuretic peptide is a strong predictor of mortality from community-acquired pneumonia independent of clinical prognostic indicators. The pathophysiological basis for this is unknown but suggests that cardiac involvement may be an under-recognised determinant of outcome in pneumonia and may require a different approach to treatment. In the meantime, measurement of B-type natriuretic peptides may help to assess prognosis.

Managing pulmonary arterial hypertension and optimizing treatment options: prognosis of pulmonary artery hypertension

Survival in patients with pulmonary artery hypertension has improved, but outcomes are still suboptimal. Therapeutic focus must shift from short-term functional changes to improvements in long-term outcomes. Several outcome predictors, both at baseline and on therapy, offer guidance for clinicians treating pulmonary artery hypertension.

Ghrelin and its relation with N-terminal brain natriuretic peptide, endothelin-1 and nitric oxide in patients with idiopathic pulmonary hypertension

OBJECTIVES

To investigate ghrelin levels in patients with idiopathic pulmonary arterial hypertension (IPAH) and the association of ghrelin with N-terminal brain natriuretic peptide (N-BNP), endothelin-1 (ET-1) and nitric oxide (NO).

METHODS

Plasma ghrelin, N-BNP, ET-1 and NO were measured, and echocardiography was performed in 20 IPAH patients and in 20 control subjects matched for age, sex and body mass index.

RESULTS

Plasma ghrelin and NT-proBNP levels were significantly higher in IPAH patients compared with values in control subjects (p < 0.05). In IPAH patients, ghrelin levels correlated positively with N-BNP (r = 0.616, p = 0.004), NO (r = 0.464, p = 0.039), right ventricle diameter (RVD; r = 0.485, p = 0.030) and pulmonary arterial systolic pressure (PASP; r = 0.591, p = 0.006). N-BNP levels correlated positively with RVD (r = 0.551, p = 0.012) and ET-1 (r = 0.451, p = 0.046).

CONCLUSIONS

Plasma ghrelin levels were elevated in IPAH. Increased ghrelin levels correlated positively with N-BNP, PASP, RVD and NO, and N-BNP levels correlated positively with RVD and ET-1. Pulmonary vascular pathology is a complex imbalance of opposing forces. Ghrelin may not only provide a novel prognostic biomarker for IPAH but also be a potential new therapeutic strategy.

Right side of heart failure

The function of the right ventricle (RV) in heart failure (HF) has been mostly ignored until recently. A 2006 report of the National Heart, Lung, and Blood Institute identified a gap between RV research efforts and its clinical importance compared with that of the left ventricle. This recent shift in paradigm is fueled by the prognostic value ascribed to RV failure in HF and morbidity/mortality after myocardial infarction and surgery. In this review, we examine the significance of RV failure in the HF setting, its clinical presentation and pathophysiology, and ways to evaluate RV function using echocardiographic measurements. Furthermore, we discuss the medical management of RV failure including traditional therapies like beta-blockers and newer options like nitric oxide, phosphodiesterase inhibitors, and calcium sensitizers. Mechanical support is also examined. Finally, this review places an emphasis on RV failure in the setting of left ventricular assist devices and heart transplantation.

Review on natriuretic peptides: where we are, where we are going

BACKGROUND

Tremendous advances have been made in our understanding of the pathophysiology and treatment of congestive heart failure. However, diagnosis of the disease still remains difficult, even with a comprehensive physical examination. Symptoms such as dyspnea are nonspecific and insensitive indicators for heart failure, which can go largely undetected. Several studies have suggested the need for new diagnostic capabilities, especially with the increasing prevalence of heart failure in the US. The discovery of natriuretic peptides as diagnostic biomarkers has been one of the most critical advances for the management of heart failure. Both B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide have the potential to diagnose heart failure, assess prognostic risk of rehospitalization and mortality, and even help guide treatment. Their relative cost-effectiveness and availability have also facilitated their acceptance into many emergency departments, clinics and in-patient units as standard care when evaluating patients with suspected heart failure. Our understanding of the natriuretic peptide system is still in its infancy, but natriuretic peptides have emerged as important diagnostic and prognostic tools that have generated interest in finding broader applications for their use.

OBJECTIVE

The purpose of this review is to discuss the clinical approaches and future applications of natriuretic peptides in diagnosing and managing treatment of congestive heart failure.

METHOD

A comprehensive review of studies to assess the utility of natriuretic peptides for diagnosis and prognosis of heart failure and other conditions.

CONCLUSION

Natriuretic peptides are powerful tools to aid the physician in the diagnosis, prognosis and management of heart failure in both in-patient and out-patient settings. However, natriuretic peptides should be used as an adjunct test as many circumstances can also influence changes in natriuretic peptide levels.

Pulmonary arterial hypertension: new insights into the optimal role of current and emerging prostacyclin therapies

Pulmonary arterial hypertension (PAH), which is a subset of pulmonary hypertension, is a group of diseases distinguished by vascular remodeling of the small pulmonary arteries with associated elevated pulmonary arterial pressure and right ventricular failure. This progressive and sometimes fatal disease occurs as an idiopathic disease or as a component of other disease states. Estimates of the incidence of PAH have varied from 5 to 52 cases/1 million population. Symptoms begin with shortness of breath with exertion and progress to dyspnea with normal activities and, finally, dyspnea at rest. Untreated patients with PAH have a 1-, 3-, and 5-year survival rate of 68%, 48%, and 34%, respectively. Treated, the survival rates improve to 91% to 97% after 1 year and 84% to 91% after 2 years. The current definition of PAH consists of 3 specific hemodynamic assessments confirmed by right heart catheterization findings. One of several important pathophysiologic mechanisms involved in PAH is pulmonary vascular remodeling, which is caused by endothelial and smooth muscle cell hyperproliferation. This is coincident with overexpression of the vasoconstrictor endothelin-1 and a reduction in the vasodilators nitric oxide and prostacyclin, which further impedes proper vasomotor tone, among other effects. Prostacyclin therapies augment the decreased prostacyclin levels in patients with PAH. The currently approved prostacyclins for the treatment of PAH include epoprostenol, iloprost, and treprostinil. Among the 3 medications, the delivery options include intravenous infusion, subcutaneous infusion, and inhaled formulations. Epoprostenol has been shown to have a positive effect on survival in patients with PAH. All prostacyclins have demonstrated improvements in functional class, exercise tolerance, and hemodynamics in patients with PAH. Intravenously and subcutaneously administered formulations of prostacyclins require continuous infusion pump administration, which presents clinical challenges for both the patient and the care provider. Dosing must be individualized and also presents a clinical challenge. Inhaled formulations seem efficacious in moderately symptomatic patients with PAH and might be appropriate when combined with an oral medication. Combination therapies are commonly used in clinical practice, with the decision to do so based on randomized controlled trial data and case study evidence. The present report provides an overview of PAH, the scientific rationale for treatment with prostacyclin therapy, and the benefits and risks of prostacyclin therapy, both as monotherapy and combined with other medications approved for the treatment of PAH.

An unexpected diagnosis in a dyspnoeic patient with primary Sjogren syndrome

We describe a case of a 50-year-old lady with newly diagnosed primary Sjogren syndrome who presented with severe pulmonary artery hypertension and pericardial effusion. She was managed by immunosuppressive agents and a combination of standard therapy for pulmonary hypertension. Our patient had a clinically significant involvement of cardio-pulmonary system that is atypical of this disease. Prompt recognition and management of this condition are extremely crucial as untreated cases carry a grave prognosis. However, the ideal treatment strategy is yet to be defined for this condition.

Utility of NT-proBNP for identifying LV failure in patients with acute exacerbation of chronic bronchitis

BACKGROUND

NT-proBNP has been widely regarded as a useful tool for diagnosis or exclusion of heart failure (HF) in many settings. However, in patients with acute exacerbation of chronic bronchitis (AECB), its roles have not been well described. The objective of this study was to evaluate the diagnostic performance of NT-proBNP for identifying left ventricular (LV) failure in such patients.

METHODS AND RESULTS

311 AECB patients and 102 stable chronic bronchitis patients with no history of HF were enrolled. Plasma NT-proBNP concentrations were measured using Roche Elecsys. The European Society of Cardiology (ESC) diagnostic principles were adopted to identify HF and the diagnostic performance of NT-proBNP was evaluated by ROC. Our results showed, the median NT-proBNP level in patients with LV failure [4828.4 (2044.4-9203.6) ng/L] was significantly higher than that in those without LV failure [519.2 (179.1-1409.8) ng/L, p<0.001] and stable controls [207.5 (186.5-318.2) ng/L, p<0.001]. LV failure, renal function, atrial fibrillation and systolic pulmonary artery pressure were independent predictors of NT-proBNP levels (all p<0.05). The area under ROC curve (AUC) of NT-proBNP for identifying LV failure was 0.884, significantly superior to clinical judgment alone (AUC 0.835, p = 0.0294). At the optimal cutoff value of 935.0 ng/L, NT-proBNP yielded sensitivity 94.4%, specificity 68.2%, accuracy 74.3% and negative predictive value 97.6%. Adding the results of NT-proBNP to those of clinical judgment improved the diagnostic accuracy for LV failure.

CONCLUSION

As a tool for diagnosis or exclusion of HF, NT-proBNP can help physicians identify LV failure in patients with AECB.

Pulmonary hypertension: biomarkers

Physicians look to biomarkers to inform the management of pulmonary hypertension (PH) at all stages, from assessing susceptibility through screening, diagnosis, and risk stratification to drug selection and monitoring. PH is a heterogeneous disorder and currently there are no accepted blood biomarkers specific to any manifestation of the condition. Brain natriuretic peptide and its N-terminal peptide have been most widely studied. Other candidate prognostic biomarkers in patients with pulmonary arterial hypertension (PAH) include growth and differentiation factor-15, red cell distribution width, uric acid, creatinine, inflammatory markers such as interleukin-6, angiopoietins, and microRNAs. Combining the measurement of biomarkers reflecting different components of the pathology with other modalities may enable better molecular characterisation of PH subtypes and permit improved targeting of therapeutic strategies and disease monitoring.

Pulmonary Hypertension in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with a variable natural history. Pulmonary hypertension (PH) is frequently found in patients with IPF and is associated with an almost 3-fold increase in the risk of death. Pulmonary hypoxic vasoconstriction plays an important role in the pathogenesis of PH in IPF (PH-IPF), although it has become clear that it is not the only mechanism involved. While invasive right heart catheterization is the gold standard modality of hemodynamic assessment, there has been increasing interest in noninvasive testing, such as Doppler echocardiogram, as complementary methods of assessing right ventricular function in these patients. While the expanding array of pharmacologic options for the treatment of pulmonary arterial hypertension has engendered increased interest in the application of these therapies for PH-IPF, supportive evidence for benefit is lacking.

NT-proBNP correlated with strain and strain rate imaging of the right ventricle before and after transcatheter closure of atrial septal defects

BACKGROUND

Atrial septal defects (ASD) account for 10% of all congenital heart lesions and represent the third most congenital cardiac defect seen in adults.

OBJECTIVES

Using strain and strain rate imaging (SRI) to assess right ventricular (RV) function in patients with ASD and correlate the results with the level of N-terminal pro-brain natriuretic peptide (NT-proBNP) before and after transcatheter closure.

METHODS

At the Hungarian Institute of Cardiology, 27 females and 18 males (mean age 21.53 years) were diagnosed with ASD and admitted for percutaneous closure. Echocardiography was done to assess theleft ventricular (LV), RV and left atrial (LA) diameters. For assessment of systolic RV function, we measured Tricuspid annular plane systolic excursion (TAPSE), strain, and SRI. Amplatzer ASD closure was done under general anesthesia. NT-proBNP levels were measured before and three months after closure.

RESULTS

ASD closure was achieved in all patients. The mean ASD diameter was 15.15 mm. The size of the occluder ranged from 10 to 24 mm. The mean LA diameter in the pre-closure group was significantly higher than the control; mean left ventricular end diastolic diameter (LVEDD) showed a non-significant difference from either the control group or the post-closure group, while the mean right ventricular end diastolic diameter (RVEDD) markedly reduced post-closure, and it was significantly higher than the control group. Global RV strain and peak systolic strain rate (PSSR) were significantly higher in ASD group than in the control. The NT-proBNP levels were found to be correlated with pulmonary arterial pressure (PAP), TAPSE, global RV strain and PSSR.

CONCLUSION

Volume overload induced by ASD is associated with increased strain values, which return to normal after closure. NT-proBNP is a parameter which correlates to RV pressure, PAP and the amount of shunt volume caused by an ASD.

Ambrisentan for the treatment of pulmonary arterial hypertension: improving outcomes

Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vasculature that is associated with severe functional impairment and a poor prognosis. Ambrisentan is a selective endothelin type A receptor antagonist approved for the treatment of patients with PAH World Health Organization group 1. The efficacy and safety of ambrisentan has been evaluated in the ARIES series (Ambrisentan for the Treatment of Pulmonary Arterial Hypertension, Randomized, Double-Blind, Placebo-Controlled, Multicenter, Efficacy Studies), which has established its use as both monotherapy or in conjunction with other PAH therapies. Specifically, ambrisentan is effective at increasing exercise tolerance, decreasing the risk of functional class deterioration, and prolonging time to clinical worsening. Further, ambrisentan has a favorable effect on mortality, with an 88% patient survival rate after two years of therapy compared with a 61% survival rate as estimated by the National Institute of Health Registry. Ambrisentan is generally well tolerated in all patient groups, with the main side effects of peripheral edema, sinusitis, flushing, and nasal congestion considered to be mild to moderate in nature. Ambrisentan has several favorable qualities that potentially make it more acceptable to patients, including once-daily administration, limited adverse drug reactions and drug-drug interactions, and minimal risk of liver enzyme elevation. Because of the potential risk of teratogenicity associated with ambrisentan, it is only available through a limited distribution program, ie, LEAP (the Letairis Education and Access Program). Ongoing clinical trials will help to clarify the role of ambrisentan in the treatment of PAH.

The natriuretic peptides as biomarkers for adults with congenital heart disease

Thanks to improved treatment of congenital heart disease early in life, many such patients reach adulthood. Adults with congenital heart disease are an increasing population, which will continue to grow in the future. The clinical state of these patients is affected by their complex heart diseases, as well as the consequence of past corrective or palliative interventions. The natriuretic peptides are important markers for the presence, severity and prognosis of heart disease. The majority of the current knowledge is on patients with acquired heart disease. This article reviews the present knowledge regarding the role of the natriuretic peptides in adults with various forms of congenital heart disease.

Pulmonary arterial hypertension: classification and therapy with a focus on prostaglandin analogs

Pulmonary arterial hypertension, part of the larger spectrum of disorders causing pulmonary hypertension, is a complex and progressive disease of multiple etiologies that ultimately leads to vascular remodeling, right-sided heart failure, and death. Advances in treatment over the past 15 to 20 years have dramatically reduced the morbidity and mortality of the disease, but often have significant drawbacks. Of the more recently approved therapies, the prostaglandin analogs have been shown to have the greatest therapeutic benefit but are also the most difficult to administer, many being given as continuous intravenous infusions in the ambulatory setting. After a case presentation highlighting some of the challenges that accompany treatment with these agents, this article reviews the diagnosis and classification of pulmonary hypertension and pulmonary arterial hypertension and gives a brief overview of the various other pharmacologic agents used in its treatment. A more comprehensive review of the biochemistry of prostaglandins and the pharmacology and clinical use of this class of drugs follows. Recommended treatment guidelines are also discussed.

Right ventricular remodeling in pulmonary hypertension

The right ventricle (RV) is in charge of pumping blood to the lungs for oxygenation. Pulmonary arterial hypertension (PAH) is characterized by high pulmonary vascular resistance and vascular remodeling, which results in a striking increase in RV afterload and subsequent failure. There is still unexploited potential for therapies that directly target the RV with the aim of supporting and protecting the right side of the heart, striving to prolong survival in patients with PAH.

Pulmonary hypertension associated with rheumatic diseases: baseline characteristics from the Korean registry

OBJECTIVES

The REgistry of Pulmonary Hypertension Associated with Rheumatic Disease (REOPARD) was established in Korea. The baseline data are described from the second year of the registry's operation.

METHODS

Patients with a connective tissue disease (CTD) who met the modified definition of the WHO group I pulmonary arterial hypertension (PAH) were enrolled. PAH was defined as a systolic pulmonary arterial pressure> 40 mmHg by echocardiography or mean pulmonary arterial pressure> 25 mmHg by right heart catheterization. Hemodynamic parameters and clinical data such as demographics, functional class, underlying disease, organ involvement, laboratory tests and current treatment were recorded.

RESULTS

A total of 321 patients were enrolled during the 2-year study period from 2008 to 2010. The mean age of the patients at registration was 51.9 years and 87.5% were female. Most patients were diagnosed by echocardiography and only 24 patients (7.5%) underwent cardiac catheterization. Exertional dyspnea was present in 63.6% of patients and 31.8% were New York Heart Association class III or IV. Among the patients, systemic lupus erythematosus accounted for 35.3%, systemic sclerosis 28.3%, rheumatoid arthritis 7.8%, overlap syndrome 9.0%, and mixed connective tissue disease 5.9%. There were no significant differences in hemodynamics, functional class, diffusing capacity and N-terminal pro-brain natriuretic peptide levels between the disease subgroups. Treatments consisted of calcium antagonists (57.0%), endothelin antagonists (32.7%), prostanoids (27.1%), phosphodiesterase-5 inhibitors (14.3%) and combinations (37.4%).

CONCLUSION

Compared with previous studies, the results showed some differences: underlying diseases, functional status and treatments. This may be due to differences in ethnic background and diagnostic methods of our study.

Plasma brain natriuretic peptide as a biomarker for haemodynamic outcome and mortality following pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

OBJECTIVES

In chronic thromboembolic pulmonary hypertension (CTEPH), right ventricular (RV) dysfunction is associated with increased morbidity and mortality following pulmonary endarterectomy. Plasma brain natriuretic peptide (BNP) levels were previously shown to correlate with RV (dys)function. We hypothesized that BNP can be used as a non-invasive biomarker to identify patients at 'high risk' for postoperative morbidity and mortality.

METHODS

We studied the postoperative outcome in 73 consecutive patients. Patients were divided into three groups based on previously determined cut-off levels: BNP <11.5, indicating normal RV function (ejection fraction [EF] ≥45%), BNP >48.5 pmol/l, indicating RV dysfunction (right ventricular ejection fraction <30%) and BNP 11.5-48.5 pmol/l. Postoperative 'bad outcome' was defined as the presence of either residual pulmonary hypertension (PH) or (all-cause) mortality.

RESULTS

Plasma BNP >48.5 pmol/l was shown to be an independent predictor of 'bad outcome'. Compared with BNP <11.5 pmol/l, BNP >48.5 pmol/l identified patients at higher risk for (all-cause) mortality (17 vs 0%; P = 0.009) and residual PH (56 vs 20%; P < 0.004). Also, the durations of mechanical ventilation and intensive care unit stay were significantly longer in patients with BNP >48.5 pmol/ml.

CONCLUSIONS

Plasma BNP levels may be of use as a non-invasive biomarker reflecting RV dysfunction, next to other well-recognized (invasive) parameters, for better preoperative risk stratification of CTEPH patients.

The potential of biomarkers in pulmonary arterial hypertension

Effective management of patients with pulmonary arterial hypertension (PAH) requires comprehensive prognostic evaluation in order to determine optimal management strategies. Although a number of clinical and hemodynamic parameters linked to PAH prognosis have been identified, some are associated with significant limitations (eg, invasive techniques, subjective measures). There is a need for noninvasive and objective measures to be established that function as biomarkers for the diagnosis and assessment of disease prognosis, and that determine response to therapy in patients with PAH. Reflecting the highly complex etiology of the disease, a large number of potential biomarkers have been, and continue to be, investigated in PAH, including those reflecting right heart function, endothelial dysfunction, and markers of inflammation and second organ failure. However, it has become clear that scientifically interesting biomarkers may not necessarily be clinically useful. Of the range of biomarkers investigated in PAH to date, only brain natriuretic peptide and its N-terminal cleavage product have been included as prognostic parameters in treatment guidelines. It is unlikely that any single biomarker will provide all the relevant information required for an individual patient, and the potential for combining markers is currently of considerable interest. Future studies are required to determine the optimal combination of existing and emerging biomarkers in the clinical setting.

Effect of obesity on B-type natriuretic peptide levels in patients with pulmonary arterial hypertension

Brain natriuretic peptide (BNP) levels are lower in obese patients with left ventricular failure than in their comparably ill, leaner counterparts. The effect of obesity on BNP in patients with pulmonary arterial hypertension (PAH) is unknown. We reviewed our prospective PAH registry data collected from November 2001 to December 2007 for patients undergoing right heart catheterization who met the criteria for PAH and had the BNP level and body mass index determined at baseline. The median BNP level for the lean, overweight, and obese patients was 285 pg/ml (interquartile range 131 to 548), 315 pg/ml (interquartile range 88 to 531), and 117 pg/ml (interquartile range 58 to 270), respectively (p = 0.029). A greater body mass index was associated with a lower BNP level, adjusted for age, gender, New York Heart Association functional class, hypertension, coronary artery disease, and mean right atrial and pulmonary arterial pressures (p <0.001). No statistically significant differences were found among the groups in age, race, medical co-morbidities, underlying etiology of PAH, use of vasoactive medications, New York Heart Association functional class, echocardiographic parameters, or pulmonary function. Obese patients had greater right atrial and pulmonary artery pressures. Increased BNP was associated with worse survival in the lean and overweight patients only. In conclusion, the BNP levels are attenuated in obese patients with PAH despite similar or worse hemodynamics or functional class compared to lean or overweight patients and should therefore be interpreted with caution.

Nicorandil prevents right ventricular remodeling by inhibiting apoptosis and lowering pressure overload in rats with pulmonary arterial hypertension

Background

Most of the deaths among patients with severe pulmonary arterial hypertension (PAH) are caused by progressive right ventricular (RV) pathological remodeling, dysfunction, and failure. Nicorandil can inhibit the development of PAH by reducing pulmonary artery pressure and RV hypertrophy. However, whether nicorandil can inhibit apoptosis in RV cardiomyocytes and prevent RV remodeling has been unclear.

Methodology/Principal Findings

RV remodeling was induced in rats by intraperitoneal injection of monocrotaline (MCT). RV systolic pressure (RVSP) was measured at the end of each week after MCT injection. Blood samples were drawn for brain natriuretic peptide (BNP) ELISA analysis. The hearts were excised for histopathological, ultrastructural, immunohistochemical, and Western blotting analyses. The MCT-injected rats exhibited greater mortality and less weight gain and showed significantly increased RVSP and RV hypertrophy during the second week. These worsened during the third week. MCT injection for three weeks caused pathological RV remodeling, characterized by hypertrophy, fibrosis, dysfunction, and RV mitochondrial impairment, as indicated by increased levels of apoptosis. Nicorandil improved survival, weight gain, and RV function, ameliorated RV pressure overload, and prevented maladaptive RV remodeling in PAH rats. Nicorandil also reduced the number of apoptotic cardiomyocytes, with a concomitant increase in Bcl-2/Bax ratio. 5-hydroxydecanoate (5-HD) reversed these beneficial effects of nicorandil in MCT-injected rats.

Conclusions/Significance

Nicorandil inhibits PAH-induced RV remodeling in rats not only by reducing RV pressure overload but also by inhibiting apoptosis in cardiomyocytes through the activation of mitochondrial ATP-sensitive K⁺ (mitoK_ATP) channels. The use of a mitoK_ATP channel opener such as nicorandil for PAH-associated RV remodeling and dysfunction may represent a new therapeutic strategy for the amelioration of RV remodeling during the early stages of PAH.

Today's and tomorrow's imaging and circulating biomarkers for pulmonary arterial hypertension

The pathobiology of pulmonary arterial hypertension (PAH) involves a remodeling process in distal pulmonary arteries, as well as vasoconstriction and in situ thrombosis, leading to an increase in pulmonary vascular resistance, right heart failure and death. Its etiology may be idiopathic, but PAH is also frequently associated with underlying conditions such as connective tissue diseases. During the past decade, more than welcome novel therapies have been developed and are in development, including those increasingly targeting the remodeling process. These therapeutic options modestly increase the patients' long-term survival, now approaching 60% at 5 years. However, non-invasive tools for confirming PAH diagnosis, and assessing disease severity and response to therapy, are tragically lacking and would help to select the best treatment. After exclusion of other causes of pulmonary hypertension, a final diagnosis still relies on right heart catheterization, an invasive technique which cannot be repeated as often as an optimal follow-up might require. Similarly, other techniques and biomarkers used for assessing disease severity and response to treatment generally lack specificity and have significant limitations. In this review, imaging as well as current and future circulating biomarkers for diagnosis, prognosis, and follow-up are discussed.

Osteopontin predicts adverse right ventricular remodelling and dysfunction in pulmonary hypertension

BACKGROUND

Osteopontin (OPN) was found upregulated in several heart failure models and appears to play an important role in myocardial remodelling. As we have previously demonstrated that OPN predicts mortality in patients with pulmonary hypertension (PH), we now evaluated whether OPN also predicts adverse right ventricular (RV) remodelling and dysfunction in PH.

METHODS

We prospectively included 71 patients with PH of different etiology in this study. OPN plasma level were determined by ELISA and assessed for correlation with RV dilatation and dysfunction determined by echocardiography.

RESULTS

OPN plasma values significantly correlated with RV end-diastolic diameter, Tricuspid Annular Plane Systolic Excursion (TAPSE) and Tricuspid Annular Systolic Velocity (TASV) (r = 0·43, P = 0·0002; r = -0·46, P = 0·0006; r = -0·31, P = 0·02). Furthermore, stratification of our study population according to RV end-diastolic diameter and RV dysfunction revealed that patients with enlarged and functionally impaired RV's display higher OPN levels (956 ng/mL vs. 628 ng/mL, P = 0·0005; 1108 ng/mL vs. 792 ng/mL; P = 0·02). Next, we determined OPN cut-off values for the detection of RV remodelling and dysfunction by receiver operating curve analyses and further stratified these parameters in a multivariate analysis. Here, OPN emerged as an independent predictor of RV dilatation and dysfunction. Finally, we demonstrate synergism of OPN and NT-proBNP in the prediction of RV dilatation and dysfunction by calculation of the Rothman Synergy Index.

CONCLUSION

In summary, OPN predicts adverse RV remodelling and dysfunction in PH. Together with our previously published data regarding OPN's value for the prognostication of death in PH, we believe that OPN can improve risk stratification in patients with PH beyond current assessment standards.

Pulmonary arterial hypertension: advances in pathophysiology and management

Pulmonary arterial hypertension (PAH) is a heterogeneous, hemodynamic, and pathophysiological state which is commonly found throughout the world, but the disease burden is greater in India and in other developing countries. It is a disease characterized by vascular obstruction and vasoconstriction leading to progressive increase in pulmonary vascular resistance and right ventricular failure. PAH is a progressive disorder carrying a poor prognosis; however, dramatic progress has occurred in our knowledge of its pathogenesis and consequently, its treatment over the last two decades. In this article, we attempt to provide an overview of the etiology, pathophysiology, and current therapeutic modalities in the treatment of PAH. Patients suspected to have PAH should be submitted to a battery of investigations which help in establishing the diagnosis, identifying the etiology, guiding in treatment and informing the prognosis. All patients should be considered for standard therapy with oxygen, anticoagulation, and diuretics for right heart failure. Oral calcium channel blockers should be used in patients with a favorable response to acute vasodilator challenge. Disease targeted therapies include prostacyclines, endothelin receptor blockers, and phosphodiesterase-5 inhibitors. A brief mention of new and potential therapeutic strategies is also included.

Whipple's disease-associated pulmonary hypertension with positive vasodilator response despite severe hemodynamic derangements

Pulmonary hypertension (PH) associated with Whipple's disease (WD-PH) is extremely rare, and the underlying pathophysiological processes are incompletely understood. Alterations in hemodynamics can be severe, with right ventricular (RV) dysfunction being common. A case involving a 23-year-old man with WD-PH who exhibited a dramatic vasodilator response during right heart catheterization despite severely altered pulmonary hemodynamics and concomitant RV dysfunction is reported. While the patient's symptoms responded poorly to treatment with nifedipine and sildenafil, significant improvement in dyspnea, RV dysfunction and pulmonary pressures were noted following antibiotic therapy. The present report highlights that despite severely elevated pulmonary artery pressures and RV dysfunction in WD-PH patients, a highly significant vasodilator response and dramatic improvement with antibiotic therapy may be observed. Furthermore, the case highlights the phenomenon of PH in the setting of inflammation, suggesting that adequate control of the inflammatory response can be accompanied by a marked improvement in hemodynamics in certain types of PH.

Comparison of baseline predictors of prognosis in pulmonary arterial hypertension in patients surviving ≤2 years and those surviving ≥5 years after baseline right-sided cardiac catheterization

Idiopathic pulmonary arterial hypertension (PAH) is usually associated with a poor outcome but the prognosis with other forms of PAH is not well-described. Advances in therapy have furthered clouded the disease course. We sought to determine the baseline indicators of prognosis in patients with PAH. We reviewed the records of patients with PAH followed up at our institution to identify those who died within 2 years (reduced survival group; n = 21) and those who survived >5 years (long survival group; n = 60). The groups were compared for prognostic significance of the baseline clinical parameters. The reduced survival group were older (p = 0.001) and more likely to have scleroderma-associated PAH (p = 0.01), have pericardial effusion (p = 0.01), have a shorter 6-minute walk test (6MWT) distance (p = 0.001), to require oxygen during 6MWT (p = 0.02), have a worse World Health Organization functional class (p <0.001), and have greater serum brain natriuretic peptide levels (p = 0.01). Regression analysis showed age, World Health Organization functional class, 6MWT distance, the need for oxygen during the 6MWT, and renal disease to be independently associated with a poor prognosis. In conclusion, age, PAH etiology, World Health Organization functional class, pericardial effusion, 6MWT distance, the need for oxygen during the 6MWT, and brain natriuretic peptide are predictors of prognosis in patients PAH receiving specific therapy and might help identify a group that could benefit from aggressive upfront therapy.